JP2019095010A - Power transmission device - Google Patents

Abstract

To suppress the generation of torsion at tooth face parts of gears due to heat for welding a clutch drum and the gears, and to suppress the deterioration of a noise level caused by the engagement of the gears.SOLUTION: A power transmission device comprises: a first power transmission path for transmitting torque via a gear mechanism; a second power transmission path for transmitting torque via a continuously variable transmission; a planetary mechanism for switching the power transmission paths; a first clutch for performing the engagement and release of the first power transmission path between an engine and the CVT; a second clutch for performing the engagement and release of the second power transmission path between the CVT and drive wheels; a first gear connected with a clutch drum having the first clutch; and a second gear arranged at a sub-axis of the second power transmission path. The first gear is composed of a weld gear part having a weld part welded with the clutch drum, and a tooth face gear part having a tooth face part, and the weld gear part and the tooth face gear part are fastened to each other by spline insertion, dog insertion or pressure insertion.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power transmission device.

  2. Description of the Related Art Conventionally, as a transmission provided in a vehicle, a structure of a continuously variable transmission (CVT) having an auxiliary transmission is known. In a CVT having an auxiliary transmission, it is necessary to provide the start gear with a clutch mechanism coupled to a planetary gear. Since the clutch mechanism and the drive gear can not be integrally molded, they need to be integrated by welding.

  Moreover, the structure of patent document 1 grade | etc., Is known as a structure of a power transmission device provided with CVT. Patent Document 1 discloses a first power transmission path for transmitting torque to an output shaft via a gear mechanism, a second power transmission path for transmitting torque to an output shaft via a continuously variable transmission, and A planetary mechanism for switching between the power transmission path and the second power transmission path, a first clutch provided between the engine and the continuously variable transmission, for switching between engagement and release of the first power transmission path, and continuously variable transmission A second clutch provided between the machine and the drive wheel for switching engagement and disengagement of the second power transmission path, a drive gear provided on the planetary shaft and to which the clutch drum of the first clutch is welded, A power transmission apparatus is described which includes a driven gear provided on a countershaft which is a power transmission path.

JP, 2015-105708, A

  In the conventional power transmission device described above, since the clutch drum having the clutch mechanism and the gear are connected by welding, the positions of the portion to be welded (welded portion) and the tooth surface portion of the gear are close. In this case, the heat generated at the time of welding causes distortion in the welded portion, so distortion occurs in the tooth flanks of the gear and the tooth flank accuracy decreases. As a result, the meshing state of the gears may be deteriorated, and the noise level of the gears may be deteriorated.

  The present invention has been made in view of the above, and an object thereof is to suppress generation of distortion in a tooth surface portion of a gear due to heat when welding a clutch drum and a gear, and by meshing of gears. An object of the present invention is to provide a power transmission device capable of suppressing the deterioration of noise level.

  In order to solve the problems described above and achieve the above object, a power transmission device according to the present invention includes a first power transmission path for transmitting torque of an engine to an output shaft via a gear mechanism, and a continuously variable transmission A second power transmission path for transmitting the torque of the engine to the output shaft via the second power source; a planetary mechanism for switching between the first power transmission path and the second power transmission path; the engine and the continuously variable transmission Between the continuously variable transmission and the drive wheels and engaging the second power transmission path, or a first clutch that engages or releases the first power transmission path. Power comprising a second clutch to be released, a first gear provided on a planetary shaft, to which a clutch drum having the first clutch is welded, and a second gear provided on a counter shaft in the second power transmission path Transmission device The first gear includes a welding gear portion having a welding portion with the clutch drum, and a tooth surface gear portion having a tooth surface portion, and the welding gear portion and the tooth surface gear portion And are characterized by being fastened by splines, dogs, or press fitting.

  According to the power transmission device of the present invention, the first gear includes the welding gear portion having the welding portion welded to the clutch drum, and the tooth surface gear portion provided with the tooth surface portion, and the welding gear portion and the tooth surface Since the gear portion is coupled by splines, it is possible to suppress the occurrence of distortion on the tooth surface portion of the first gear due to the heat when welding the clutch drum and the gear, and suppress the deterioration of the noise level due to the meshing of the gears. It becomes possible.

FIG. 1 is a skeleton diagram showing a schematic configuration of a power transmission device according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view showing the configuration of the peripheral portion of the forward gear mode clutch and forward and reverse rotation output gear that constitute the transmission mechanism in the power transmission apparatus according to one embodiment of the present invention. FIG. 3 is a partial sectional view showing a state in which peripheral portions of the forward gear mode clutch and the forward / reverse rotation output gear shown in FIG. 2 are divided. FIG. 4 is a side view showing the configuration of the peripheral portion of the forward gear mode clutch and forward and reverse rotation output gear that constitute the transmission mechanism in the power transmission device according to the prior art. FIG. 5 is a partial cross-sectional view showing a configuration of a peripheral portion of a forward gear mode clutch and forward and reverse rotation output gear that constitute a transmission mechanism in a power transmission device according to the prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals. Further, the present invention is not limited by the embodiments described below.

  First, a vehicle provided with a power transmission device according to an embodiment of the present invention will be described. FIG. 1 is a skeleton diagram showing a schematic configuration of a power transmission device according to this embodiment.

  As shown in FIG. 1, the power transmission device 1 for a vehicle Ve according to this embodiment has a first axis AX 1, a second axis AX 2, a third axis AX 3, a fourth axis AX 4, and a fifth axis AX 5 parallel to one another. Axis line. The first axis AX1 is coaxial with a crankshaft (not shown) provided in the engine. On the first axis AX1, the input shaft 3 of the power transmission system 1 of the vehicle Ve connected to the crankshaft of the engine, the torque converter 4, the primary shaft 7, the planetary gear DP as a planetary mechanism, the clutch C1 for forward gear mode, reverse A primary brake 11 of a brake B1 and a belt type continuously variable transmission (hereinafter, CVT) 10 is disposed. That is, the forward gear mode clutch C1 as the first clutch is disposed around the primary shaft 7.

  A reduction gear mechanism 20 is disposed on the second axis AX2. The secondary pulley 13 of the CVT 10, the belt mode clutch C2, and the output gear portion 30 are disposed on the third axis AX3. The countershaft portion 40 is disposed on the fourth axis AX4. A differential device 50 and left and right drive shafts 52L and 52R are disposed on the fifth axis AX5.

  The input shaft 3 is connected to the pump impeller 4 a of the torque converter 4. The torque converter 4 includes a pump impeller 4 a, a turbine runner 4 b, a stator 4 c, and a lockup clutch 5. The turbine runner 4 b is disposed opposite to the pump impeller 4 a and connected to the primary shaft 7. The stator 4 c is disposed between the pump impeller 4 a and the turbine runner 4 b and is connected to a one-way clutch (not shown) supported by the transmission case 6. The lockup clutch 5 brings the input shaft 3 and the primary shaft 7 into a direct connection state by engaging the input shaft 3 and the primary shaft 7. The inside of the torque converter 4 is oil-filled and oil-tight.

  The primary shaft 7 as a planetary shaft is connected to the primary pulley 11 of the CVT 10 through the inner peripheral side of the planetary gear DP. The primary shaft 7 is connected to the carrier CR of the planetary gear DP. The planetary gear DP has a sun gear S, a ring gear R, and a carrier CR. The carrier CR rotatably supports a pinion P1 meshing with the sun gear S and a pinion P2 meshing with the ring gear R, respectively. That is, the planetary gear DP is configured by a so-called double pinion planetary gear. The ring gear R is configured such that its rotation can be locked against the transmission case 6 by the reverse brake B1. The sun gear S is directly connected to the hollow shaft 8. The carrier CR is connected to the hollow shaft 8 via the forward gear mode clutch C1. The hollow shaft 8 is connected to the forward and reverse rotation output gear 9. The hollow shaft 8 is connected to a clutch drum 60 described later provided with a forward gear mode clutch C1. The hollow shaft 8, the forward / reverse rotation output gear 9, and the clutch drum 60 integrally constitute a rotating member. The hollow shaft 8 and the forward and reverse rotation output gear 9 as the first gear mesh with the input gear 21 of the reduction gear mechanism 20.

  The reduction gear mechanism 20 as a gear mechanism has a central shaft 22 as a sub shaft on the second axis AX2. In the reduction gear mechanism 20, a large diameter input gear 21 as a second gear and a small diameter drive gear 23 are integrally fixed and connected to one side of the central shaft 22. The hollow shaft 26 is relatively rotatably supported on the outer peripheral side of the other side of the central shaft 22. A driven gear 25 having the same diameter as the drive gear 23 and an output gear 27 slightly larger in diameter than the drive gear 23 and the driven gear 25 are integrally fixed to and connected to the hollow shaft 26.

A sleeve 24 is disposed on the outer peripheral side of the drive gear 23 and the driven gear 25. The sleeve 24 has a tooth surface formed on the inner peripheral surface, and is axially movable by a hydraulically driven spoke (not shown). The sleeve 24 can move along the axial direction between a position in which only the drive gear 23 meshes and a position in which both the drive gear 23 and the driven gear 25 are meshed. Thus, the drive gear 23 and the driven gear 25 are configured to be switchable to the separated state or the driven connection state by the sleeve 24. Further, the output gear 27 meshes with an input gear 31 of an output gear portion 30 described later. The transmission gear ratio of the reduction gear mechanism 20 is set to a transmission gear ratio larger than the maximum transmission gear ratio γ _max of the belt type CVT 10 described later.

  The CVT 10 includes a primary pulley 11, a secondary pulley 13, and a transmission belt 15. Primary pulley 11 is connected to primary shaft 7. The secondary pulley 13 is connected to the secondary shaft 16. The endless transmission belt 15 is wound around the primary pulley 11 and the secondary pulley 13. The primary pulley 11 is composed of a fixed sheave 11a and a movable sheave 11b. The stationary sheaves 11 a have wall surfaces formed in the form of truncated cones facing each other, and are fixed so as not to be movable in the axial direction with respect to the primary shaft 7. The movable sheave 11 b is supported movably in the axial direction with respect to the primary shaft 7. The transmission belt 15 is held by a groove formed by the wall surfaces of the fixed sheave 11 a and the movable sheave 11 b. Similarly, the secondary pulley 13 is composed of a fixed sheave 13a and a movable sheave 13b. The stationary sheaves 13 a have wall surfaces formed in the form of truncated cones facing each other, and are axially immovably fixed to the secondary shaft 16. The movable sheave 13 b is supported movably in the axial direction with respect to the secondary shaft 16. The transmission belt 15 is nipped by a groove formed by the wall surfaces of the fixed sheave 13a and the movable sheave 13b. The stationary sheave 11 a of the primary pulley 11 and the stationary sheave 13 a of the secondary pulley 13 are disposed on the opposite side of the transmission belt 15 in the axial direction.

  The CVT 10 includes hydraulic servos 12 and 14. The hydraulic servo 12 is disposed on the back side of the movable sheave 11 b of the primary pulley 11. The hydraulic servo 14 is disposed on the back side of the movable sheave 13 b of the secondary pulley 13. The hydraulic servos 12 and 14 generate a belt clamping pressure corresponding to the load torque and generate a clamping pressure for changing or fixing the gear ratio γ of the CVT 10 by supplying the hydraulic pressure.

  The movable sheave 13b of the secondary pulley 13 is connected to the output shaft 32 of the output gear unit 30 via a belt mode clutch C2 as a second clutch. The output gear unit 30 includes an input gear 31, an output shaft 32, and a counter gear 33. The output shaft 32 is relatively rotatably supported on the outer peripheral side of the secondary shaft 16, and one end side thereof is fixed to the input gear 31. The counter gear 33 is fixed to the other end side of the output shaft 32 and is in mesh with the drive gear 41 of the counter shaft portion 40.

  The countershaft portion 40 is configured of a drive gear 41, a countershaft 42, and a driven gear 43. One end side of the counter shaft 42 is fixed to the drive gear 41. The other end side of the counter shaft 42 is fixed to the driven gear 43. The driven gear 43 meshes with the differential ring gear 51 of the differential device 50.

  The differential device 50 is configured to transmit the rotation of the differential ring gear 51 to the left and right drive shafts 52L and 52R while absorbing their differential rotation. The left and right drive shafts 52L and 52R are respectively connected to left and right drive wheels (not shown).

  Next, the operation of the power transmission 1 will be described. First, when the vehicle Ve equipped with the power transmission device 1 selects the forward gear (D range) by the driver's operation of the shift device (not shown) and starts moving forward, or travels forward at less than a predetermined vehicle speed May. In this case, in the power transmission device 1, the sleeve 24 is switched so as to be engaged across the drive gear 23 and the driven gear 25 in a state where the reverse brake B1 and the belt mode clutch C2 are released, and for the forward gear mode The clutch C1 is engaged to enter the forward gear mode.

  In the forward gear mode, when the forward gear mode clutch C1 is engaged, the planetary gear DP is brought into a direct connection state in which the sun gear S and the carrier CR rotate integrally. Thereby, the engine torque input to the input shaft 3 is transmitted to the hollow shaft 8 via the torque converter 4 or the lockup clutch 5, the primary shaft 7 and the planetary gear DP. The input rotation transmitted to the hollow shaft 8 is transmitted from the forward and reverse rotation output gear 9 to the input gear 21 of the reduction gear mechanism 20 as normal rotation. The input rotation transmitted to the input gear 21 of the reduction gear mechanism 20 is decelerated by the difference in diameter between the forward and reverse rotation output gear 9 and the input gear 21 as forward rotation, that is, the difference in the number of teeth. The forward rotation transmitted to the input gear 21 is transmitted as a reverse rotation to the output gear 27 from the drive gear 23 through the sleeve 24 and the driven gear 25. The reverse rotation transmitted to the output gear 27 is transmitted to the input gear 31 of the output gear unit 30 as normal rotation.

  The forward rotation transmitted to the input gear 31 of the output gear unit 30 is further transmitted from the counter gear 33 to the drive gear 41 of the counter shaft unit 40 by the difference in diameter between the counter gear 33 and the drive gear 41, that is, the difference in the number of teeth. It is transmitted as reverse rotation while being decelerated. The decelerated reverse rotation transmitted to the drive gear 41 of the countershaft portion 40 is further decelerated and reversely transmitted from the driven gear 43 and transmitted to the diff ring gear 51 of the differential device 50. The forward rotation of the fixed gear ratio as the forward gear mode is output to the drive wheels via the left and right drive shafts 52L, 52R. That is, in the forward gear mode, the torque output from the engine is output shaft 32 of output gear portion 30 via planetary gear DP, forward / reverse rotation output gear 9 and reduction gear mechanism 20 which are the first power transmission path. Transmitted to

When the vehicle speed becomes equal to or higher than the predetermined vehicle speed during traveling in the forward gear mode, the gear ratio γ of the CVT 10 is set to the maximum gear ratio γ _max or the gear ratio γ close to the maximum gear ratio γ _max . In this state, the engagement of the sleeve 24 with the driven gear 25 is released, the forward gear mode clutch C1 is released, and the belt mode clutch C2 is engaged to switch to the belt mode.

  In the belt mode, the engine torque input to the input shaft 3 is transmitted from the torque converter 4 or the lockup clutch 5 and the primary pulley 11 via the transmission belt 15 to the secondary pulley 13 as a continuously variable transmission while being continuously changed. Be done. The continuously variable transmission rotation transmitted to the secondary pulley 13 is transmitted to the output shaft 32 of the output gear unit 30 via the belt mode clutch C2. The continuously variable transmission rotation transmitted to the output shaft 32 is transmitted from the counter gear 33 to the drive gear 41 of the counter shaft portion 40. The continuously variable transmission rotation transmitted to the drive gear 41 of the countershaft portion 40 is transmitted to the differential ring gear 51 of the differential device 50 while being decelerated by the driven gear 43. Thereby, the normal rotation of the variable transmission ratio as the belt mode is output to the drive wheels via the left and right drive shafts 52L and 52R. That is, in the belt mode, the torque output from the engine is transmitted to the output shaft 32 of the output gear unit 30 via the CVT 10, which is the second power transmission path, and the belt mode clutch C2.

When the vehicle Ve decelerates to a stop while the vehicle Ve is traveling in the belt mode, coast down control switches from the belt mode to the forward gear mode when the gear ratio γ of the CVT 10 returns to the maximum gear ratio γ _max. To be implemented. As a result, it is possible to reduce the shift shock that may occur when switching from the belt mode to the forward gear mode by setting the gear ratios of the CVT 10 and the reduction gear mechanism 20 close to each other.

  When the vehicle Ve equipped with the power transmission device 1 selects a reverse gear (R range) by the driver's operation of the shift device and starts moving in a reverse direction, or travels backward at less than a predetermined vehicle speed, the clutch for forward gear mode C1 and the belt mode clutch C2 are released. In this state, the sleeve 24 is switched to mesh over the drive gear 23 and the driven gear 25, and the reverse brake B1 is engaged to shift to the reverse gear mode.

  In the reverse gear mode, when the reverse brake B1 is engaged, since the ring gear R of the planetary gear DP is fixed, the input rotation of the carrier CR is reversed by the ring gear R and is output from the sun gear S as reverse rotation. Thereby, the engine torque input to the input shaft 3 is transmitted to the hollow shaft 8 via the torque converter 4 or the lockup clutch 5, the primary shaft 7 and the planetary gear DP. In this case, the input rotation input to the hollow shaft 8 is transmitted from the forward and reverse rotation output gear 9 to the input gear 21 of the reduction gear mechanism 20 as reverse rotation. The input rotation transmitted to the input gear 21 of the reduction gear mechanism 20 is decelerated by the difference in diameter between the forward and reverse rotation output gear 9 and the input gear 21 as in the forward gear mode, that is, the difference in the number of teeth. The reverse rotation transmitted to the input gear 21 is transmitted from the drive gear 23 to the output gear 27 as normal rotation via the sleeve 24 and the driven gear 25. The forward rotation transmitted to the output gear 27 is transmitted to the input gear 31 of the output gear unit 30 as reverse rotation.

  The reverse rotation transmitted to the input gear 31 of the output gear portion 30 is further decelerated by the difference in diameter between the counter gear 33 and the drive gear 41 from the counter gear 33 to the drive gear 41 of the counter shaft portion 40, that is, the difference in the number of teeth. It is transmitted as normal rotation while being The decelerated forward rotation transmitted to the drive gear 41 of the countershaft portion 40 is further decelerated and inverted from the driven gear 43 and transmitted to the differential ring gear 51 of the differential device 50. The reverse rotation of the fixed gear ratio as the reverse gear mode is output to the drive wheels via the left and right drive shafts 52L, 52R. That is, in the reverse gear mode, the torque output from the engine is transmitted through the planetary gear DP, the forward / reverse rotation output gear 9 and the reduction gear mechanism 20, which are the first power transmission path, to the output shaft 32 of the output gear unit 30. Transmitted to

  Next, peripheral configurations of the forward gear mode clutch C1 and the forward / reverse rotation output gear 9 will be described. FIG. 2 is a partial cross-sectional view showing the configuration of the periphery of the forward gear mode clutch C1 and the forward / reverse rotation output gear 9 that constitute the transmission mechanism 2 in the power transmission device 1 according to this embodiment. FIG. 3 is a partial sectional view showing a state in which peripheral portions of the forward gear mode clutch C1 and the forward / reverse rotation output gear 9 shown in FIG. 2 are divided.

  As shown in FIGS. 2 and 3, the transmission mechanism 2 according to this embodiment includes a clutch drum 60, a welding gear portion 61, and a tooth surface gear portion 62. In addition, in FIG. 2 and FIG. 3, the structure of the upper part from the rotating shaft O is described. The clutch drum 60 is fitted on the outer peripheral surface of the primary shaft 7 while accommodating the forward gear mode clutch C1 on the inner peripheral side. On the inner peripheral side of the clutch drum 60, a sun gear S or the like of the planetary gear DP is disposed along the hollow shaft 8. The sun gear S is integrally fixed to the clutch drum 60 and provided on the outer peripheral side of the hollow shaft 8.

  The clutch drum 60 is welded to and connected to the welding gear portion 61 at the welding portion 63. The welding gear portion 61 has various portions to be fitted into the clutch drum 60. The tooth surface gear portion 62 has forward and reverse rotation output gear 9 as a tooth surface portion. The welding gear portion 61 and the tooth surface gear portion 62 are respectively provided with spline engaging portions 61s and 62s at portions facing each other. The welding gear portion 61 and the tooth surface gear portion 62 are integrally fastened by spline engagement in which spline engaging portions 61s and 62s facing each other are engaged. Thus, the clutch drum 60 is engaged with the forward / reverse rotation output gear 9. The sun gear S is rotatably supported relative to the tooth surface gear portion 62 by an angular contact ball bearing 64. The sun gear S and the forward / reverse rotation output gear 9 are configured to be integrally rotatable.

  In the clutch drum 60, outer friction plates 71a are alternately arranged between the inner friction plates 71b of the forward gear mode clutch C1. The outer friction plate 71a is spline-engaged with splines 60s formed on the inner peripheral surface of the drum portion 60a of the clutch drum 60 disposed on the outer peripheral side. A stopper 72 for positioning the outer friction plate 71a in the axial direction with respect to the drum portion 60a is fixed to the opening side of the drum portion 60a. The clutch drum 60 is integrally connected to the hollow shaft 8. A radially extending oil passage c3 is formed in the hollow shaft 8 in order to supply lubricating oil to the inner friction plate 71b and the outer friction plate 71a of the forward gear mode clutch C1.

  A hydraulic servo 80 of the forward gear mode clutch C1 is disposed on the tooth surface gear 62 side of the planetary gear DP. The forward gear mode clutch C1 includes a friction plate 71 including an outer friction plate 71a and an inner friction plate 71b, and a hydraulic servo 80 for connecting and disconnecting the friction plate 71. The hydraulic servo 80 is partially constituted by the clutch drum 60 and has a piston 81, a clutch balancer 82, and a return spring 83. The clutch drum 60, the piston 81, the clutch balancer 82, and the return spring 83 constitute a hydraulic fluid chamber 84 and a cancel fluid chamber 85.

  The piston 81 is slidably fitted on the outer peripheral side of the hollow shaft 8 along the axial direction. A clutch balancer 82 is fitted on the side of the planetary gear DP of the piston 81 and is axially positioned by a snap ring 86. The piston 81 is disposed movably in the axial direction in the cylinder portion 60c, and a return spring 83 formed of, for example, a compression coil spring is compressed between the piston 81 and the clutch balancer 82. The piston 81 constitutes a hydraulic oil chamber 84 between the cylinder portion 60c and the cylinder portion 60c by the two seal members a1 and a2. An oil passage c1 formed in the hollow shaft 8 is in communication with the hydraulic fluid chamber 84 for allowing the hydraulic fluid to flow into and out of the hydraulic fluid chamber 84. In this embodiment, the forward gear mode clutch C1 and the hydraulic servo 80 are separately provided. However, the hydraulic servo 80 may be configured as part of the forward gear mode clutch C1.

  On the outer peripheral side of the piston 81, a pressing portion 81a is extended. The pressing portion 81 a is disposed to face the friction plate 71 and is configured to be able to press the friction plate 71. Splines are formed on the outer peripheral surface of the pressing portion 81a, and are engaged with splines 60s formed on the inner peripheral side of the drum portion 60a.

  The movement of the clutch balancer 82 to the side of the planetary gear DP is restricted by a snap ring 86 fitted to the hollow shaft 8. The clutch balancer 82 constitutes an oil tight cancel oil chamber 85 by the seal member a3. The cancellation oil chamber 85 is in communication with an oil passage c2 formed in the hollow shaft 8 for causing the hydraulic oil to flow in and out of the cancellation oil chamber 85. The clutch balancer 82 is always biased based on the biasing force of the return spring 83 or the hydraulic pressure of the cancel oil chamber 85, and is fixed to the hollow shaft 8.

  The oil passage c1 is in communication with a hydraulic oil passage (not shown) communicating with the hydraulic control device. When hydraulic fluid flows from the oil passage c1 into the hydraulic fluid chamber 84, the piston 81 slides against the return spring 83 and presses the friction plate 71 of the forward gear mode clutch C1. The pressing force of the piston 81 is transmitted from the friction plate 71 through the stopper 72 to the carrier CR (see FIG. 1). Thereby, the hollow shaft 8 and the clutch drum 60 and the carrier CR are connected via the forward gear mode clutch C1.

  FIG. 4 is a side view showing the configuration of the peripheral portion of the forward gear mode clutch and the forward / reverse rotation output gear in the power transmission device according to the prior art. FIG. 5 is a partial cross-sectional view showing the configuration of the peripheral portion of the forward gear mode clutch and the forward / reverse rotation output gear in the power transmission device according to the prior art. In addition, in FIG. 5, the structure of the upper part from the rotating shaft O is described.

  As shown in FIG. 4, in the conventional power transmission device, the clutch drum 60 and the gear portion 100 are connected by welding. That is, the hollow shaft 8 in the gear portion 100 and the sun gear S of the planetary gear DP are inserted into the opening 65 of the clutch drum 60. Thereafter, the inner circumferential portion 65a of the opening 65 and the outer circumferential portion 100a of the insertion portion of the gear portion 100 are fitted, and the inner circumferential portion 65a and the outer circumferential portion 100a are welded and connected.

  The power transmission device is manufactured by welding as described above because the integral molding of the clutch drum 60 storing the forward gear mode clutch C1 and the gear portion 100 is difficult. Then, although the method of processing the tooth surface of forward / reverse rotation output gear 9 after welding is considered, it is difficult to realize in practice, and the method of connecting clutch drum 60 and gear portion 100 by welding is adopted. The

  However, as shown in FIG. 5, when the clutch drum 60 and the gear portion 100 are connected by welding, distortion due to heat at the time of welding occurs in the portion of the encircling portion A in FIG. Due to heat distortion at the time of welding, the weld portion 101 is deformed, for example, in the direction of the arrow in FIG. The forward and reverse rotation output gear 9 is disposed at a position close to the welding portion 101 because of space and other performance problems. Therefore, when the welding portion 101 is deformed, the tooth surface of the forward / reverse rotation output gear 9 is displaced by the deformation of the welding portion 101, and the tooth surface accuracy is changed. By shifting the tooth flanks of the forward and reverse rotation output gear 9, the level of noise of the gear is aggravated and the level variation is increased. This causes the generation of a booming noise and the like.

  On the other hand, in the embodiment described above, instead of the gear portion 100, the welding gear portion 61 and the tooth surface gear portion 62 are divided. Further, spline engaging portions 61s and 62s are provided on the welding gear portion 61 and the tooth surface gear portion 62, respectively. Then, as shown in FIG. 2, after inserting the insertion portion of the welding gear portion 61 into the opening 65 of the clutch drum 60 in the same manner as in the prior art, in the welding portion 63 the inner peripheral portion 65a of the opening 65 and the welding gear Weld the part 61. Thereafter, as shown in FIG. 3, the spline engaging portion 61s of the welding gear portion 61 and the spline engaging portion 62s of the tooth surface gear portion 62 are engaged with each other to form the welding gear portion 61 and the tooth surface gear portion 62. Let it conclude. In this case, the distortion caused by the deformation of the welding portion 63 is absorbed by the welding gear portion 61 and does not affect the tooth surface gear portion 62. Therefore, since the tooth flank accuracy of the forward / reverse rotation output gear 9 in the tooth flank gear portion 62 does not change, it is possible to suppress the deterioration of the level of the noise of the gear and to reduce the level variation.

  As mentioned above, although one Embodiment of this invention was described concretely, this invention is not limited to one above-mentioned embodiment, Various deformation | transformation based on the technical idea of this invention are possible. For example, the numerical values listed in the above-described embodiment are merely examples, and different numerical values may be used as needed.

  For example, in the above-described embodiment, the welding gear portion 61 and the tooth surface gear portion 62 are fastened by splines, but can be fastened by dogs or press-fitting.

Reference Signs List 1 power transmission device 2 transmission mechanism 3 input shaft 7 primary shaft 8, 26 hollow shaft 9 forward / reverse rotation output gear 10 belt type continuously variable transmission (CVT)
Reference Signs List 20 reduction gear mechanism 21, 31 input gear 22 central shaft 27 output gear 30 output gear portion 32 output shaft 60 clutch drum 61 weld gear portion 61s, 62s spline engagement portion 62 tooth surface gear portion 63 weld portion

Claims (1)

A first power transmission path for transmitting the torque of the engine to the output shaft via the gear mechanism;
A second power transmission path for transmitting the torque of the engine to the output shaft via a continuously variable transmission;
A planetary mechanism for switching between the first power transmission path and the second power transmission path;
A first clutch provided between the engine and the continuously variable transmission for engaging or releasing the first power transmission path;
A second clutch provided between the continuously variable transmission and the drive wheel for engaging or releasing the second power transmission path;
A first gear provided on a planetary shaft, to which a clutch drum having the first clutch is welded;
And a second gear provided on the countershaft in the second power transmission path.
The first gear is configured to include a welding gear portion having a welding portion with the clutch drum, and a tooth surface gear portion having a tooth surface portion.
The power transmission device, wherein the welding gear portion and the tooth surface gear portion are fastened by splines, dogs, or press fitting.

Images